Using commas inside a macro without parenthesis: How can I mix and match with a template?

Question

Consider a simple macro:

#define ECHO(x) x

ECHO(foo(1, 2))

This produces the exact output we expect:

foo(1, 2)
         


        

Answer 1

#define COMMA ,
ECHO(template)

A little painful, but it works.

FWIW, if the syntax for the argument allows ()s, you don't need the substitution, e.g.,

ECHO((a, b))

will work for a single argument macro but that doesn't work in all cases (including yours).